1. Field of the Invention
This invention relates to a method of producing a chip-type solid-electrolyte capacitor.
2. Description of the Prior Art
Previously, various chip-type solid-electrolyte capacitors have been proposed. An example of them is shown in FIG. 1, which is manufactured by such a method that an anode terminal 22 and a cathode terminal 23 are respectively connected to a capacitor body 21 which is fabricated by a known method, and a resin layer 24 is formed by the transfer molding technique on the surface of the capacitor body 21 for the sheathing purpose as well as the outer end portions of the anode terminal 22 and the cathode terminal 23 are respectively protruded from the sheathing resin layer 24.
With the electrolyte capacitor as structured as above, since the leading section of each of the anode terminal 22 and the cathode terminal 23 for protruding is to be contained into the sheathing resin layer 24 as shown in FIG. 1, the sheathing resin layer 24 is unavoidably large in volume, arising such a problem that compactization is extremely difficult. Then, in order to overcome this problem, a chip-type solid-electrolyte capacitor as shown in FIG. 2 has been proposed.
In FIG. 2, a resin layer 33 is provided for the sheathing purpose on the surface of an anode body 31 having an anode lead 32 vertically inserted thereinto excepting the end surface of the anode body 31 opposite to the end surface where the anode lead 32 is inserted. On the surface of the end portion of the anode body 31 on the side of the anode lead 32 are laminated an electroconductive layer 34, a plated metal layer 35 and a solder layer 36 so as to contact respectively with the anode lead 32. On the surface of the end portion of the anode body 31 on the opposite side to the anode lead 32 is formed an electroconductive layer 37 so as to contact with the surface portion of the anode body 31 where the sheathing resin layer 33 is not provided, and a plated metal layer 38 and a solder layer 39 are laminated thereon in this order. The electroconductive layer 34, the plated metal layer 35 and the solder layer 36 constitute an anode, and on the other hand, the electroconductive layer 37, the plated metal layer 38 and the solder layer 39 constitute a cathode.
In addition, in the capacitor shown in FIG. 2, such a capacitor that the electroconductive layers 34 and 37 are not formed and the plated metal layers 35 and 38 and the solder layers 36 and 39 are respectively laminatedly formed directly on the surface of the anode body 31 is known as well.
The capacitor shown in FIG. 2 is smaller in size than that shown in FIG. 1. However, it has been pointed out such a problem that when it is mounted on a circuit substrate, it is easy to be disconnected therefrom when an external force is applied.
Thus, an object of this invention is to provide a method of producing a chip-type solid-electrolyte capacitor which is small in size and yet hard to be disconnected even under the application of an external force from a circuit substrate on which it is mounted.